US President Donald Trump has dismissed the option of diplomatic negotiations with North Korea, declaring that "talking is not the answer" just a day after Pyongyang fired a ballistic missile over Japan, drawing international condemnation.

Key points:

US senator slams Donald Trump's tweet as "most irresponsible of his presidency"

North Korea promises more missiles, particularly in the Pacific around Guam

Russian Foreign Minister Sergei Lavrov spoke by telephone with US Secretary of State Rex Tillerson and urged the US to refrain from any military action on the Korean peninsula that would be "fraught with unpredictable consequences", Russia's Foreign Ministry said.

North Korea has said the latest launch of an intermediate-range ballistic missile (IRBM) was to counter US and South Korean military drills and was a first step in military action in the Pacific to "contain" the US island territory of Guam.

The US-drafted statement, which did not threaten new sanctions on North Korea, urged all nations to implement UN sanctions and said it was of "vital importance" that Pyongyang take immediate, concrete actions to reduce tensions.

North Korea this month threatened to fire four missiles into the sea near Guam, home to a major US military presence, after Mr Trump said the North would face "fire and fury" if it threatened the United States.

The latest tweet by the US President drew criticism from Congressmen in Washington.

"Bar is high, but this is perhaps the most dangerous, irresponsible tweet of his entire Presidency," Senator Chris Murphy tweeted.

"The current ballistic rocket launching drill like a real war is the first step of the military operation of the KPA [Korean People's Army] in the Pacific and a meaningful prelude to containing Guam," KCNA quoted Mr Kim as saying.